Arrangment and method for processing a substrate

ABSTRACT

An arrangement for processing a substrate has an ion source for production of ions for processing the substrate using at least one process gas, and a process gas supply device, which is coupled to the ion source, in order to supply the process gas into the ion source. The process gas supply device has a tube composed of electrically insulating material, as well as a process gas supply regulator, which is designed such that the process gas is supplied at a pressure which is lower than the ambient pressure in the tube.

The invention relates to an arrangement and a method for processing a substrate.

Within the framework of processing a substrate, for example a semiconductor substrate, it may be desirable to dope the latter with doping ions by means of an ion implantation method.

For this purpose, an ion beam is usually generated from a doping gas stream, and said beam is directed to the semiconductor substrate. The doping ions that penetrate the semiconductor substrate form contaminants in the semiconductor substrate grid that alter the properties of the semiconductor substrate.

As a doping gas, often a highly toxic and/or slightly inflammatory gas is used, such as, for example, phosphine (PH₃), arsine (AsH₃), boron trifluoride (BF₃), or silicon tetrafluoride (SiF₄). To avoid third parties from being endangered by such a doping gas during the processing of a substrate, such a doping gas is usually provided in a specially configured gas cylinder, which is set up in such a way that it releases the process gas only under negative pressure, whereby the gas cylinder, however, has only a limited absorbing capacity. This results in that, on the one hand, the gas cylinder has to be changed frequently, and, on the other hand, that it may occur that a processing of a substrate cannot be completely terminated, since the filling level of the respective gas cylinder can be monitored only with difficulty or not at all. A filling level monitoring would also result in that the respective gas cylinder had to be changed before it is completely empty, which in turn would lead to a considerable scrapping of the residual content of the gas cylinder. This in turn results in increased unusable doping gas waste, which results in high production costs.

In various embodiments, a feeding of process gas into a processing device for processing a substrate is achieved with increased safety, as well as with simplified replacement of a process-gas reservoir, for example, one or more gas cylinders. For example, in various embodiments, a process gas supply is prepared in a substrate working process, whereby the risk is reduced, or it is completely prevented so that it results in electrical flashovers in feeds and at the same time the risk that is created by possible leaks of the pipe is reduced.

An arrangement for processing a substrate according to one embodiment has an ion source for generating ions for processing the substrate with use of at least one process gas, as well as a process-gas feeding device—coupled to an ion source—for feeding the process gas to an ion source. The process-gas feeding device has a pipe that is made of electrically insulating material as well as a process-gas feed controller that is set up in such a way that the process gas is fed at a pressure that is below the ambient pressure of the pipe.

The ion source can be at an electrical potential of at least 1,000 V, for example at an electrical potential of at least 10,000 V.

In addition, the substrate-processing device can have an ion beam generating device. The ion source can be contained in the ion beam generating device.

In addition, a substrate-processing device can be provided for processing the substrate, whereby the ion source in the substrate-processing device can be provided. The substrate-processing device can be set up as a substrate-ion implanter or as a plasma-substrate-processing device, for example as a plasma-etching device or as a plasma-deposition device. Thus, the substrate-processing device can be, for example, a substrate processing chamber.

In addition, a process-gas reservoir or several process-gas reservoirs can be provided in the arrangement, and said reservoir(s) is/are connected to the pipe for feeding the process gas or process gases to the pipe or the pipes.

The process-gas reservoir can be arranged outside of the substrate-processing device, in other words physically separated from the substrate-processing device, for example from the substrate processing chamber. For example, for this reason, a potential difference can be present between the electrical potential, which exists with or in the ion source (for example because of the process for generating the ions that is to be performed and that is provided there), and the electrical potential, which exists in the process-gas reservoir (this potential is often and also usually desirable in the case of approximately zero volt). By means of the pipe that is made of electrically insulating material, the usual limitations that are produced from the potential difference can be overcome, and the process-gas reservoir can easily be arranged in an area outside of the substrate-processing device, for example in a space of a central gas supply for a number of ion sources, for example for a number of substrate-processing devices, which in each case have at least one ion source. In this way, the maintenance or the exchange of one or more process-gas reservoirs is also considerably simplified, without impairing the safety in the framework of the gas supply, since, for example, the transport of the process gas in the pipe is carried out at a pressure that is below the ambient pressure of the pipe, whereby a discharge of the process gas is safely prevented.

In one embodiment, the process-gas reservoir can thus be at an electrical potential that is different (for example by at least 1,000 V, for example by at least 10,000 V) from the electrical potential of the ion source.

The electrically insulating material can be plastic, ceramic, or glass.

Also, the pipe can be a double pipe with an inside pipe and an outside pipe, whereby the inside pipe and the outside pipe are produced from electrically insulating material. The inside pipe can be set up (and, for example, equipped) for absorbing the process gas. Also, the outside pipe can be set up (and, for example, equipped) for absorbing a buffer gas.

In the example in which the pipe is a double pipe with an inside pipe and an outside pipe, the process-gas feed controller is set up in such a way that the process gas is fed at a pressure that is below the ambient pressure of the outside pipe of the pipe.

The buffer can be a different gas than the process gas. For example, the buffer gas can be an inert gas.

In one embodiment, the arrangement in addition has a buffer-gas feed controller, which is set up in such a way that the buffer gas is fed to the outside pipe at a pressure that is different from the pressure (i.e., higher or lower than the pressure) with which the process gas is fed to the inside pipe. The buffer-gas feed controller can be formed together with the process-gas feed controller (for example in a common control housing) or as a control that is independent from the process-gas feed controller.

In another embodiment, the process-gas feed controller can be set up in such a way that the process gas is fed at a pressure that is below atmospheric pressure (ambient to the application).

The process-gas feed controller can be set up in such a way that the process gas is fed at a pressure that is lower by approximately 1% to approximately 15% of the ambient pressure of the pipe than the ambient pressure of the pipe, for example lower by approximately 2% to approximately 10% of the ambient pressure of the pipe than the ambient pressure of the pipe, and for example lower by approximately 4% to approximately 6% of the ambient pressure of the pipe than the ambient pressure of the pipe.

As explained above, a majority or a large number of ion sources can be provided in the arrangement and a majority or a large number of related process-gas feeding devices in each case, which respectively have a pipe that is made of electrically insulating material (for example a single-walled pipe or a double-walled pipe).

Thus, in one embodiment, at least one additional ion source can be provided in the arrangement for generating ions for processing at least one substrate (the same substrate, which is processed by means of the ion source or another substrate) with use of at least one process gas (the same process gas, by means of which the substrate is processed or another process gas), as well as at least one additional process-gas feeding device that is coupled to at least one additional ion source for feeding process gas into at least one additional ion source. The at least one additional process-gas feeding device can have a pipe that is made of electrically insulating material. The process-gas feed controller can be set up in such a way that the at least one additional process gas is fed at a pressure that is below the ambient pressure of the pipe of at least one additional process-gas feeding device.

In a method for processing a substrate, at least one process gas is fed by means of a process-gas feeding device to an ion source for generating ions, whereby the process-gas feeding device has a pipe that is made of electrically insulating material. Also, the substrate is processed by means of the ion source with use of at least one process gas, and the process gas is fed into the pipe at a pressure that is below the ambient pressure of the pipe.

The ion source can be at an electrical potential of at least 1,000 V, for example at an electrical potential of at least 10,000 V.

In one configuration of the method, an ion beam can be generated from at least one process gas by means of the ion source. For example, a substrate-ion implantation or a plasma-substrate processing can be performed by a substrate-processing device, in which the ion source can be contained.

Also, the process gas can be fed from a process-gas reservoir to the pipe. The process-gas reservoir can be arranged outside of the substrate-processing device.

According to one embodiment, the process-gas reservoir is at an electrical potential that is different from the electrical potential of the ion source. The process-gas reservoir can be at an electrical potential that is at least 1,000 V, for example at least 10,000 V (for example in a range of approximately 5,000 V to approximately 250,000 V), different from the electrical potential of the ion source.

In addition, plastic, ceramic or glass can be used as the electrically insulating material.

In one embodiment, the pipe can be a double pipe with an inside pipe and an outside pipe, whereby the inside pipe and the outside pipe are produced from an electrically insulating material.

The process gas can be fed into the inside pipe, and a buffer gas can be fed into the outside pipe.

The buffer gas can be a different gas than the process gas. For example, the buffer gas can be an inert gas.

In one embodiment, the buffer gas is fed to the outside pipe at a pressure that is higher than the pressure at which the process gas is fed to the inside pipe. As an alternative, the buffer gas can be fed to the outside pipe at a pressure that is below the pressure at which the process gas is fed to the inside pipe. The difference between the pressure in the inside pipe and the pressure in the outside pipe serves, for example, to determine a leak in the inside pipe. In general, in one embodiment, the buffer gas can thus be fed to the outside pipe at a pressure that is different from the pressure at which the process gas is fed to the inside pipe.

In addition, the process gas can be fed at a pressure that is below the atmospheric pressure.

For example, the process gas is fed at a pressure that is approximately 1% to approximately 15% of the ambient pressure of the pipe below the ambient pressure of the pipe, for example lower by approximately 2% to approximately 10% of the ambient pressure of the pipe than the ambient pressure of the pipe, for example lower by approximately 4% to approximately 6% of the ambient pressure of the pipe than the ambient pressure of the pipe.

Embodiments of the invention are depicted in the figures and are explained in more detail below.

Here

FIG. 1: shows an arrangement for processing a substrate according to one embodiment;

FIG. 2: shows an arrangement for processing a substrate according to another embodiment;

FIG. 3: shows a depiction of components of a substrate-processing arrangement from FIG. 2 according to one embodiment; and

FIG. 4: shows a flow chart, in which a method for processing a substrate according to one embodiment is shown.

In the framework of this specification, the terms “connected,” “hooked up,” and “coupled” are used to describe both a direct and an indirect connection and a direct or indirect hookup, as well as a direct or indirect coupling. In the figures, identical or similar elements are provided with identical reference numbers, if this is suitable.

FIG. 1 shows an arrangement 100 for processing a substrate according to one embodiment.

The arrangement 100 has a substrate-processing device 102, for example an ion implanter, alternatively, for example, a plasma-etching chamber or a plasma-deposition chamber. In the example of an ion implanter 102, a hand-over point 114 is arranged in a gas box 104. The gas box 104 is arranged in an outside housing 106, in which an inside housing 108 is also arranged. In one embodiment, the inside housing 108 (for example made of metal), is divided, whereby two parts 180, 182 are made electrically insulated from one another (for example by means of insulators 172). One part 180 of this is at a presettable reference potential, such as for example, ground potential 174 (for example, zero potential), and the other part 182 is at an elevated electrical potential (for example at least 5 kV, for example at least 10 kV, for example in a range of approximately 5 kV to approximately 250 kV). Also, the outside housing 106 can be at a presettable reference potential, such as, for example, the ground potential 174 (for example, zero potential). As is explained in greater detail below, a pipe 110 that is made of electrically insulating material is fed through the outside housing 106 to the hand-over point (also referred to as hookup 114 below) in the gas box 104 to feed a process gas that is used within the framework of the processing of the substrate. In one embodiment, the gas box 104 and the components found therein are at a high electrical potential, for example of at least approximately 5 kV (for example at least approximately 80 kV) up to approximately 250 kV.

In the inside housing 108, for example, a substrate carrier 176 is also provided, on which a substrate 178 can be arranged that is to be doped by means of the doping ions that are generated by the ionization source 112 (also referred to as ion source within the framework of this specification).

In one embodiment, the substrate-processing device 102 is arranged in a clean room or an ultra-clean room. In one embodiment, the inside housing 108 is a housing that can be evacuated to a high vacuum (for example at a pressure in a range of approximately 10⁻³ to 10⁻⁷ mbar) or ultra-high vacuum (for example, at a pressure in a range of less than 10⁻⁷ mbar). The hookup 114 to feed the process gas is made in the gas box 104. With this hookup 114, the pipe 110 that is described in greater detail below (for example the inside pipe 148) is connected in a gastight manner. In one embodiment, the hookup 114 understandably forms a transition between the pipe 110 (for example the inside pipe 148) and thus understandably between an electrically insulating process-gas line and to an additional electrically conductive process-gas line 170, which in turn can be connected to the ionization source 112. In one embodiment, the outside housing 106 encloses the inside housing 108 and optionally the gas box 104 (in which, for example, valves and mass flow regulators are contained). Thus, for example, the additional electrically conductive process-gas line 170 as well as the ionization source 112 are at a high electrical potential, for example at least approximately 5 kV (for example at least approximately 80 kV) up to approximately 250 kV.

In one embodiment, a housing that can be evacuated can be defined as a housing that makes it possible to reduce the gas pressure in the interior to below 10⁻³ mbar, for example to less than 10⁻⁷ mbar (millibar). This allows good guiding and forming of, for example, the ion beam, without interactions with gas molecules resulting inside the inside housing 108.

The substrate can be a wafer substrate, which can be produced from various semiconductor materials. Thus, the substrate can be produced from, for example, a group IV (of the periodic table) semiconductor material, such as, for example, silicon or germanium. As an alternative, the substrate can be produced from, for example, a group III or group V semiconductor material or one or more semiconductor materials of other main or secondary groups of the periodic table. In one example, the substrate is formed from an insulating material, such as, for example, silicon oxide. Also, the substrate can be formed from a polymer. In one embodiment, the wafer substrate is produced from silicon (doped or undoped); alternatively, the wafer substrate is a silicon-on-insulator substrate (silicon on insulator). As an alternative, any other suitable semiconductor material can be used for the substrate, for example, compound semiconductor materials such as, e.g., gallium-arsenide (GaAs), indium-phosphide (InP), but also any other suitable ternary or quaternary compound semiconductor material, such as, e.g., indium-gallium-arsenide (InGaAs).

In the example of the ion implanter 102, the latter has an ionization source (symbolized in FIG. 1 with the reference number 112), for example as part of an ion beam generating device. The ionization source 112 of an ion implanter 102 is at an electrical potential relative to the ground potential (for example, zero potential) of usually at least approximately 5 kV (for example at least approximately 80 kV) up to approximately 250 kV. In various embodiments, the substrate-processing device 102 in the processing of the substrate is at a presettable reference potential, for example ground potential. Also, in various embodiments, the gas box 104 and the ionization source 112 in the inside housing 108 are at an electrical potential compared to the ground potential of at least 1,000 V, for example at least 10 kV. The ionization source 112 (and the processing of the substrate that is to be processed) is arranged in the inside housing 108.

The electrical potential of the ionization source 112 determines the energy of the ionized doping atoms in the ion beam. In this way, the penetration depth of the doping into the substrate 178 can be specified.

For processing the substrate, it is usually provided that the process gas that is used for processing is brought to this electrical potential. In the example of the ion implanter 102, the gas(es) that is/are used for doping the substrate (the process gas or the process gases) is/are brought to this electrical potential. As is explained in greater detail below, in various embodiments, a process-gas reservoir or several process-gas reservoirs is/are provided (for example, one or more gas cylinders), which store(s) the process gas(es) and prepare(s) it/them for processing, after moving out of the substrate-processing device 102 (for example outside of the ion implanter 102), for example out of the clean room or the ultra-clean room, into a separately provided gas chamber, which is physically separated from the processing area (also referred to as the manufacturing area), in which the substrate-processing device 102 and thus the ionization source 112 are arranged.

In this way, the provision of special gas cylinders that would usually be operated under negative pressure at the high electrical potential of the ion source 112 can be avoided in order to prevent personal injury and also contamination of the environment in the case of an opened gas cylinder valve (or in the case of leaks). According to various embodiments, the necessary handling expense is reduced as also the amount of unplanned down time of the substrate-processing device 102. Also, a content monitoring of the content of the gas cylinder is made possible or simplified, whereby the interruptions of running manufacturing processes can be reduced. Thus, the scrapping risk is also reduced. Also, in various embodiments, the risk of the discharge of toxic gases into, for example, the clean room or the ultra-clean room can be reduced. In various embodiments, moreover, after the exchange of a respective gas cylinder, the process can be continued without interruption and finished without the product being damaged. In other words, this means that a gas cylinder can be exchanged without resulting in an interruption of the process.

The amount of scrap produced can be further reduced, for example, if every process-gas reservoir is designed to be redundant, for example in the form of several gas cylinders that can be flexibly turned on and/or switched.

As described above, the arrangement 100 also has a process-gas reservoir 116 or several process-gas reservoirs 116, for example containing one or more gas cylinders 118, as well as correspondingly related controllers and components for safety monitoring. In one embodiment, at least one gas cylinder 118 is configured conventionally, so that the process gas that is stored in the gas cylinder 118 is stored at overpressure.

As is explained in greater detail below, the process-gas reservoir 116 is connected to several lines and/or pipes and by means of the latter supplies the substrate-processing device 102 with the process gas that is provided in each case.

In the example of the ion implanter 102, the process gas can be a doping gas.

The doping gas can contain, for example, compounds of at least one of the following doping elements: phosphorus (P), arsenic (As), antimony (Sb), boron (B), aluminum (Al), indium (In), gallium (Ga), germanium (Ge), carbon (C), hydrogen (H), chlorine (Cl), oxygen (0), bromine (Br), nitrogen (N), silicon (Si), fluorine (F), and/or selenium (Se).

In various embodiments, the doping gas can contain or be at least one of the following gases: arsine (AsH₃), phosphine (PH₃), boron trifluoride (BF₃), and/or silicon tetrafluoride (SiF₄).

These gases are suitable for the generation of an ion beam. In various embodiments, doping elements phosphorus (P), arsenic (As), boron (B), and silicon (S) are suitable.

Several lines are guided into the process-gas reservoir 116, for example a process-gas line 122 that is connected to at least one gas cylinder 118 by means of a first valve 120, a pumping line 126 that is connected to at least one gas cylinder 118 by means of a second valve 124, as well as a flushing line 130 that is guided into the process-gas reservoir 116 and connected by means of a third valve 128 to the latter.

The first valve 124 as well as the additional valves that are described below can be, for example, pneumatically actuatable valves, for example high-grade steel valves. Instead of the valves, also other suitable devices can be used for controlled blocking and passing of a gas stream.

The process-gas line 122, the pumping line 126, and/or the flushing line 130 can be produced from electrically conductive material, for example from a metal (e.g., from steel, for example from high-grade steel). The process-gas line 122, the pumping line 126, and/or the flushing line 130 can be at a defined electrical potential, for example, on the ground potential, and can be single-walled or double-walled.

The flushing line 130 can be a nitrogen (N₂) flushing line 130, by means of which the lines 122, 126, 130 can be flushed with a flushing gas, for example, with nitrogen (N₂), whereby the feeding of the flushing gas is controlled by means of a fourth valve 132.

The pumping line 126 is used, for example, to pump gases from the process-gas reservoir 116. In one embodiment, the pumping line 126 is connected by means of a Venturi nozzle 134 to an exhaust line 136 as well as by means of a fifth valve 138 to a nitrogen-vacuum line 140. The Venturi nozzle 134 is connected to a pressure sensor (not shown) to monitor the pumping.

The process-gas line 122 is connected to two pressure regulators that are connected in series, for example two pressure-reducing devices. In one embodiment, an input of a first pressure-reducing device 142 is connected to the process-gas line 122. In one embodiment, the first pressure-reducing device 142 has a regulation range of up to approximately 200 bar (on the input side) up to approximately 4 bar (on the output side). An output of the first pressure-reducing device 142 is connected to an input of a second pressure-reducing agent 144. In one embodiment, the second pressure-reducing agent 144 has a regulation range of up to approximately 40 bar (on the input side) up to approximately 0 bar (absolute pressure) (on the output side). It can be pointed out that in an alternative embodiment, only one pressure-reducing device can be provided when the latter has a sufficiently large regulating area. When using several pressure-reducing devices (for example, even three or more pressure-reducing devices that are connected in series), an increased degree of safety is achieved. Understandably, a pressure reduction in the process gas that is fed to the pressure-reducing devices 142, 144 is thus carried out by means of the pressure-reducing devices 142, 144 down to approximately 0 bar, if desired, for example up to approximately 950 mbar (for example 70 mbar below ambient-atmospheric pressure), in one embodiment down to nearly below the ambient pressure of the pipe 110 (for example down to approximately 1% to approximately 15% of the ambient pressure of the pipe 110 below the ambient pressure of the pipe 110), for example down to nearly below the atmospheric pressure. At the outputs of the pressure-reducing devices 142, 144, in each case manometers, in other words, pressure sensors, can be provided to monitor and regulate the respectively desired gas pressure. For example, the pressure is selected in such a way that the puncture strength of the insulation element in the pipe 110 remains unchanged, and in the case of a possible leak (for example in the inside pipe 148), the process gas (e.g., the doping gas) does not go into the atmosphere. The gas cylinder pressure can be reduced to the operating pressure by the multi-stage (for example two-stage) pressure reduction.

The process gas that is prepared at the output of the second pressure-reducing device 144 is fed by means of a sixth valve 146 to the pipe 110 that is connected to the latter.

In one embodiment, the pipe 110 is a double pipe, for example in the form of a plastic hose with an inside hose 148 (in general an inside pipe 148) to feed the process gas and with an outside hose 150 (also referred to below as a buffer hose) (in general an outside pipe 150) that is provided coaxially around the inside hose 148 and filled with a buffer gas. The outside pipe 150 has a larger diameter than the inside pipe 148.

The inside pipe 148 and the outside pipe 150 are both produced from electrically insulating material, for example from a plastic, as an alternative ceramic or glass. The inside pipe 148 and the outside pipe 150 can both be produced from the same electrically insulating material or from different electrically insulating materials. In one embodiment, the inside hose 148 and/or the outside hose 150 is/are produced from tetrafluoroethylene/perfluoroalkoxy/vinyl ether-copolymerizate (PFA) (in one alternative embodiment, the inside hose 148 and/or the outside hose 150 is/are produced from polyvinylidine fluoride (PVDF)). The pipe 110 can, for example, depending on the desired electrical strength, have a length in a range of approximately 20 cm (for example provided in an ion implanter 102, which is operated at an electrical potential of at least 80 kV) up to approximately 1.5 m (for example, provided in an ion implanter 102, which is operated at an electrical potential of approximately up to 250 kV). Depending on the length of the pipe and based on the process gas that is used, the process gas is fed at a pressure (i.e., the process-gas feed controller 152 is set up in such a way that the process gas is fed at a pressure) that is high enough (i.e., higher than a minimum breakdown voltage of the process gas, optionally plus a presettable tolerance range, for example in a range of 5%, for example 10, up to, for example, 20% of the minimum breakdown voltage of the process gas), so that a sufficient electrical puncture strength of the insulation element in the pipe 110 is ensured. Understandably, a pressure-resistant pipeline that is made of an electrically non-conductive material (e.g., PFA/PVDF) with a low leakage rate is thus provided in an embodiment for overcoming the potential distance. The pressure-resistant pipeline that is made of electrically non-conductive material can be made double-walled, whereby the ring gap can be filled with inert gas in overpressure, which prevents a discharge of, for example, doping gases outward or can be detected via a drop in pressure.

The buffer gas (a different gas than the process gas, for example an inert gas, for example an inert gas whose atomic weight clearly differs from the atomic weight of the doping element in the doping gas; for example, the buffer gas is nitrogen, argon and/or sulfur hexafluoride) is filled in one embodiment at a pressure in the outside pipe 150 that is different from the pressure (for example, is higher or lower than the pressure) at which the process gas is guided through the inside pipe 148. In one embodiment, the pressure at which the buffer gas is filled into the outside pipe 150 is higher than the ambient pressure of the pipe 110, for example higher than the atmospheric pressure. In one embodiment, the pressure at which the buffer gas is filled into the outside pipe 150 is in a range of approximately 1 bar to approximately 11 bar, for example in a range of approximately 1 bar to approximately 5 bar, for example in a range of approximately 1.5 bar to approximately 3.0 bar. Within the framework of this specification, the pressure information is defined in bar as absolute pressure.

The pressure at which the process gas is guided into the inside pipe 148 is set and regulated in one embodiment by means of a process-gas feed controller 152, which is connected, for example, between the sixth valve 146 and an inlet of the inside pipe 148, whereby for this purpose, the process-gas feed controller 152 activates the first pressure-reducing device 142 and/or the second pressure-reducing device 144 by means of a control line 184. A typical volume flow of the process gas for an implanter is in a range of approximately 0.1 sccm up to approximately 10 sccm (standard cubic centimeter per minute). With a volume flow in this range, an essentially full supply to, for example, the ionization source, can be ensured.

In the outside pipe 150, the buffer gas can be filled and then statically stored in the outside pipe 150 by means of a seventh valve 154 that is connected to the outside pipe 150 (for example for filling the buffer gas) and an eighth valve 156 that is also connected to the outside pipe 150 (for example for removing the buffer gas and thus for emptying the outside pipe 150). It is to be noted that the seventh valve 154 can be connected in an alternative embodiment to an electrically conductive part of the lines. The buffer gas, however, can be exchanged at regular intervals. This is used, on the one hand, for dehydrating the buffer gas and, on the other hand, for avoiding enriching the buffer gas with the possibly toxic process gas. As an alternative, the buffer gas can also be guided into a continuous gas stream through the outside pipe at the set or regulated desired pressure. The buffer gas is used, on the one hand, to protect the environment from the process gas, for example the doping gas, and is used, on the other hand, to detect a leak in the inside pipe 148. In one embodiment, the buffer gas is filled into the outside pipe 150 and sealed. In this connection, “sealed” means, for example, that in the case of the intact inside pipe 148 and outside pipe 150, a change of the buffer gas, for example relative to the composition and/or the pressure of the buffer gas, can take place only by diffusive processes through the wall of the outside pipe 150 and/or through the wall of the inside pipe 148.

The pressure at which the buffer gas is guided into the outside pipe 150 is set in one embodiment by means of a buffer-gas feed controller 158, which is connected, for example, between the seventh valve 154 and an input of the outside pipe 150.

On the outside pipe 150, a ninth valve 160 and/or a tenth valve 162 is/are optionally provided, by means of which a desiccant 164 is hooked up to the outside pipe 150. The outside pipe 150 that is made of electrically insulating plastic possibly may not be diffusion-tight. The desiccant 164 can be contained in a box 166, for example in a cartridge 166. As an alternative, the desiccant 164 can also be filled into the outside pipe 150 itself. In one embodiment, the desiccant 164 is silica gel. It is to be noted that the ninth valve 160 and/or the tenth valve 162 and thus the box 166 in an alternative embodiment can be hooked up to an electrically conductive part of the lines.

In one embodiment, an additional exhaust 168 (made of an electrically non-conductive material) attached to the outside housing 106 of the substrate-processing device 102 is provided. By means of additional possibly provided optional pressure sensors, for example hooked up to the pipe 110 or to the exhaust 168, a pressure monitoring can be ensured in the areas desired in each case. The pressure monitoring can be carried out continuously and/or intermittently (for example by means of one or more manometers). When the pressure of the buffer gas drops, it can be assumed that there is a leak in the pipe 110. For example, in this connection, a time analysis of the pressure plot of the buffer gas and/or at least one process gas can be provided, in which, for example, a greater drop of pressure of the buffer gas is evaluated as an indication of a leak in the pipe 110, for example in the inside pipe 148, and a corresponding reaction can be provided.

The pipe 110 that is made of electrically insulating material makes it possible to operate the process-gas reservoir 116 at a different electrical potential, for example at the ground potential, than the ionization source 112. Thus, in one embodiment, the process-gas reservoir is at an electrical potential that is different from the electrical potential of the ionization source 112, for example different by at least 1,000 V, for example different by at least 10,000 V.

In one embodiment, a central gas supply for a substrate-processing device, for example an ion implanter, is provided, with a gas cabinet in a separate gas chamber, optionally including a gas-monitoring device and corresponding safety circuits. The process gas(es) is/are fed via a high-voltage-resistant supply line, for example to the pipe 110 that is made of electrically insulating material, the substrate-processing device, and thus an ion source. In addition, in one embodiment, the central gas supply can be set up with sufficient aeration and can be equipped with filters.

Also, the arrangement 100 can have a control unit (not shown) that is connected by means of a data line to, for example, one or more pressure sensors, for example, in the form of a processor, for example a microprocessor. A respective pressure sensor can forward the pressure data detected by it to the control unit by means of the data line. In the control unit, the data that is forwarded to it (for example data that describe the gas pressure in the inside pipe 148 and/or outside pipe 150) are collected and analyzed. In this way, a pressure monitoring at the desired position in each case is made possible within the arrangement 100, for example a pressure monitoring of the pipe 110. In other words, with use of the collected data by the control unit, for example by means of an analysis of the time plot (the time change of the pressure), it is monitored whether a leak is present in the pipe 110, for example in the inside pipe 148 and/or in the outside pipe 150. If this should be the case, according to one embodiment, a warning to an operator is initiated by the control unit, and/or the supply of the process gas is (immediately) ended. In addition, the high voltage of the unit optionally can be turned off.

In addition, the control unit can be connected to gas sensors by means of additional data lines that monitor for leaks the connecting points of the pipe 110 to the ionization source and a gray-scale table, which is explained in greater detail below. The gas sensors can be designed so that they can detect a few ppb (parts per billion, parts in one billion particles) of the process gas(es) (for example doping gases) in other gases. Based on the detection results of the gas sensors, in one embodiment, a warning to an operator can also take place and/or an interruption of the supply of the process gas(es) can be provided. In one embodiment, the pressure of the process gas in the inside pipe 148 is at approximately 0.9 bar, the pressure of the buffer gas in the outside pipe 150, for example, is at more than approximately 1.5 bar, for example in a range of approximately 2.0 bar to approximately 3.0 bar. In an increase of the pressure of the process gas in the inside pipe 148, which indicates a leak in the inside pipe 148, the control unit can issue a warning and/or the supply of process gas can be ended. This can be done with use of the respective valves.

FIG. 2 shows an arrangement 200 for processing a substrate according to one other embodiment.

The arrangement has several central gas barriers 202, 204, 206, for example a first gas barrier 202, in which phosphine (PH₃) is stored in one or more gas cylinders, a second gas barrier 204, in which arsine (AsH₃) is stored in one or more gas cylinders, as well as a third gas barrier 206, in which boron trifluoride (BF₃) is stored in one or more gas cylinders.

Also, the arrangement shows a number of substrate-processing arrangements 208, substrate-processing arrangements 208 in the depicted Example 17. Each of the substrate-processing arrangements 208 is connected by means of a respective process-gas line 210, 212, 214 to the respective central gas barriers 202, 204, 206, so that the prepared process gases that are provided can be fed by means of the respective gas lines 210, 212, 214 to each of the substrate-processing arrangements 208. In one embodiment, a first process-gas line 210, on the one hand, is hooked up to the first gas barrier 202 to supply phosphine (PH₃), and, on the other hand, to those substrate-processing arrangements 208 (for example to all substrate-processing arrangements 208) in which phosphine (PH₃) is required as a process gas. In addition, in one embodiment, a second process gas line 212, on the one hand, is hooked up to the second gas barrier 204 to supply arsine (AsH₃), and, on the other hand, to those substrate-processing arrangements 208 (for example to all substrate-processing arrangements 208) in which arsine (AsH₃) is required as a process gas. Finally, in one embodiment, a third process gas line 214, on the one hand, is hooked up to the third gas barrier 206 to supply boron trifluoride (BF₃), and, on the other hand, to those substrate-processing arrangements 208 (for example to all substrate-processing arrangements 208) in which boron trifluoride (BF₃) is required as a process gas.

In one embodiment, the process-gas lines 210, 212, 214 are single-walled or double-walled metal lines, for example made of steel, for example made of high-grade steel.

In addition, the arrangement has several pressure sensors, for example manometers, for monitoring pressure in the process-gas lines 210, 212, 214. In the case of double-walled process-gas lines 210, 212, 214, outside-pipe pressure sensors 216, 218, 220 can be provided, which are hooked up to the respective outside pipes of the process-gas lines 210, 212, 214 for monitoring the pressure of the buffer gases, which are filled into the respective outside pipes of the process-gas lines 210, 212, 214. In one embodiment, a first outside-pipe pressure sensor 216 is connected to the outside pipe of the first process-gas line 210, a second outside-pipe pressure sensor 218 is connected to the outside pipe of the second process-gas line 212, and a third outside-pipe pressure sensor 220 is connected to the outside pipe of the third process gas line 214. Also, in the case of the double-walled process-gas lines 210, 212, 214, inside-pipe pressure sensors 222, 224, 226 can be provided, which are hooked up to the respective inside pipes of the process-gas lines 210, 212, 214 for monitoring the pressure of the process gases, which are filled into the respective inside pipes of the process-gas lines 210, 212, 214. In one embodiment, a first inside-pipe pressure sensor 222 is connected to the inside pipe of the first process gas line 210, a second inside-pipe pressure sensor 224 is connected to the inside pipe of the second process-gas line 212, and a third inside-pipe pressure sensor 226 is connected to the inside pipe of the third process-gas line 214.

In one embodiment, optionally additional valves 228, 230, 232 are also provided that are hooked up to the respective outside pipes of the process-gas lines 210, 212, 214 to supply/remove the buffer gases, whereby a first outside-pipe valve 228 is connected to the outside pipe of the first process-gas line 210, a second outside-pipe valve 230 is connected to the outside pipe of the second process-gas line 212, and a third outside-pipe valve 232 is connected to the outside pipe of the third process-gas line 214.

Each of the substrate-processing arrangements 208 can have the components that are shown in FIG. 3 and described below:

-   -   A gray-table device 300, for example having input connections         with intake valves 302, 304, 306 for hooking up the process-gas         lines 210, 212, 214, for example for hooking up the inside pipes         of the process-gas lines 210, 212, 214, so that the respective         process gases from the gray-table device 300 can be collected         and prepared by means of additional control valves 308, 310, 312         and gray-table lines 314, 316, 318 of output hookups 320, 322,         324 of a transfer device 344 (also referred to below as a         transfer box 344). The gray-table device 300 also has flushing         lines 326, 328, 330, by means of which, for example, nitrogen         (N₂) can be fed to the gray-table lines 314, 316, 318 with use         of flushing valves 332, 334, 336. In addition, the gray-table         device 300 can have a first exhaust device 338 as well as a         second exhaust device 340 for removing exhaust from the         gray-table device 300. A gray-table gas-monitoring device 342         can be hooked up to the exhaust devices 338, 340 to monitor the         exhaust gases.     -   The transfer device 344 is connected by means of its input         hookups 346, 348, 350 to the gray-table lines 314, 316, 318 to         collect the process gases that are prepared by the latter. In         addition to an exhaust device 352 and a transfer-box         gas-monitoring device 354 that is hooked up thereto for         monitoring the exhaust gases of the transfer box 344, the         transfer box 344 has transfers 356, 358, 360 for sending gases         from lines made of electrically conductive material (for example         metal, for example high-grade steel) to lines/pipes made of         electrically insulating material (such as, for example, plastic         or ceramic).     -   Pipes 362, 364, 366, in each case set up and operated in the         same way as the pipe 110 in FIG. 1, for feeding process gases to         a substrate-processing device 368. Each of the pipes 326, 364,         366 that is made of electrically insulating material is hooked         up, on the one hand, to an output hookup of a related transfer         356, 358, 360 and, on the other hand, to a related input hookup         370, 372, 374 of the substrate-processing device 368, and then         to a related gas-box-input hookup 376, 378, 380 of a         processing-device gas box 382 of the substrate-processing device         368.     -   The substrate-processing device 368, for example an ion         implanter 368, which has an ionization source, as described         above, which is arranged in a processing-device gas box 382.

As is shown in FIG. 3, the gray-table device 300, the transfer device 344, as well as the substrate-processing device 368 are at a presettable (low) reference potential, for example the ground potential 384 (for example, zero potential). The gas box and a portion of the processing device (referred to in FIG. 3 with reference number 382) are in an embodiment at the above-described high electrical potential 386.

FIG. 4 shows a flow chart 400, in which a method for processing a substrate according to one embodiment is shown.

In 402, at least one process gas is fed by means of a process-gas feeding device to an ion source to generate ions, whereby the process-gas feeding device has a pipe that is made of electrically insulating material.

In 404, the substrate is processed by means of the ion source with use of at least one process gas.

Also, in 406, the process gas is fed into the pipe at a pressure that is below the ambient pressure of the pipe.

Although the invention has been shown and described primarily in connection with specific embodiments, it should be understood by ones skilled in the art that many different changes can be made to the configuration and the details thereof without departing from the essence and scope of the invention, as defined by the claims below. The scope of the invention is therefore determined by the attached claims, and it is intended that all changes that are within the scope of the meaning and the equivalency range of the claims be comprised by the claims. 

1. Arrangement for processing a substrate, With an ion source for generating ions for processing the substrate with use of at least one process gas; With a process-gas feeding device that is coupled to the ion source for feeding the process gas into the ion source; Whereby the process-gas feeding device has a pipe that is made of electrically insulating material as well as a process-gas feed controller, which is set up in such a way that the process gas is fed at a pressure that is below the ambient pressure of the pipe.
 2. Arrangement according to claim 1, whereby the ion source is at an electrical potential of at least 1,000 V.
 3. Arrangement according to claim 2, whereby the ion source is at an electrical potential of at least 10,000 V.
 4. Arrangement according to claim 1, with an ion beam-generating device, whereby the ion beam-generating device has the ion source.
 5. Arrangement according to claim 1, With a substrate-ion implanter, whereby the substrate-ion implanter has the ion source; or With a plasma-substrate-processing device, whereby the plasma-substrate-processing device has the ion source.
 6. Arrangement according to claim 1, with a process-gas reservoir, which is connected to the pipe for feeding the process gas into the pipe.
 7. Arrangement according to claim 6, with a substrate-processing device, in which the ion source is arranged, whereby the process-gas reservoir is arranged outside of the substrate-processing device.
 8. Arrangement according to claim 6, whereby the process-gas reservoir is at an electrical potential that is different from the electrical potential of the ion source.
 9. Arrangement according to claim 8, whereby the process-gas reservoir is at an electrical potential that is at least 1,000 V different from the electrical potential of the ion source.
 10. Arrangement according to claim 9, whereby the process-gas reservoir is at an electrical potential that is at least 10,000 V different from the electrical potential of the ion source.
 11. Arrangement according to claim 1, whereby the electrically insulating material is plastic, ceramic or glass.
 12. Arrangement according to claim 1, whereby the pipe is a double pipe with an inside pipe and an outside pipe, whereby the inside pipe and the outside pipe are produced from electrically insulating material.
 13. Arrangement according to claim 12, Whereby the inside pipe is set up to collect process gas; and Whereby the outside pipe is set up to collect a buffer gas.
 14. Arrangement according to claim 13, whereby the buffer gas is a different gas than the process gas.
 15. Arrangement according to claim 14, whereby the buffer gas is an inert gas.
 16. Arrangement according to claim 13, with a buffer-gas feed controller, which is set up so that the buffer gas is fed at a pressure to the outside pipe or is fed at the pressure that is different from that at which the process gas is fed to the inside pipe.
 17. Arrangement according to claim 1, whereby the process-gas feed controller is set up in such a way that the process gas is fed at a pressure that is below the atmospheric pressure.
 18. Arrangement according to claim 1, whereby the process-gas feed controller is set up in such a way that the process gas is fed at a pressure that is approximately 1% to approximately 15% of the ambient pressure of the pipe below the ambient pressure of the pipe.
 19. Arrangement according to claim 1, With at least one additional ion source for generating ions for processing at least one substrate with use of at least one process gas; With at least one additional process-gas feeding device that is coupled to at least one additional ion source for feeding the process gas into at least one additional ion source; Whereby at least one additional process-gas feeding device has a pipe that is made of electrically insulating material; and Whereby the process-gas feed controller is set up in such a way that at least one additional process gas is fed at a pressure that is below the ambient pressure of the pipe of at least one additional process-gas feeding device.
 20. Method for processing a substrate, Whereby at least one process gas is fed by means of a process-gas feeding device to an ion source for generating ions, whereby the process-gas feeding device has a pipe that is made of electrically insulating material; Whereby the substrate is processed by means of the ion source with use of at least one process gas; and Whereby the process gas is fed into the pipe at a pressure that is below the ambient pressure of the pipe.
 21. Method according to claim 20, whereby the ion source is at an electrical potential of at least 1,000 V.
 22. Method according to claim 21, whereby the ion source is at an electrical potential of at least 10,000 V.
 23. Method according to claim 20, whereby an ion beam that consists of at least one process gas is generated by means of the ion source.
 24. Method according to claim 20, whereby a substrate-ion implantation or a plasma-substrate processing is implemented.
 25. Method according to claim 20, whereby the process gas is fed from a process-gas reservoir to the pipe.
 26. Method according to claim 25, whereby the process-gas reservoir is arranged outside of a substrate-processing device, in which the ion source is arranged.
 27. Method according to claim 25, whereby the process-gas reservoir is at an electrical potential that is different from the electrical potential of the ion source.
 28. Method according to claim 27, whereby the process-gas reservoir is at an electrical potential that is at least 1,000 V different from the electrical potential of the ion source.
 29. Method according to claim 28, whereby the process-gas reservoir is at an electrical potential that is at least 10,000 V different from the electrical potential of the ion source.
 30. Method according to claim 20, whereby plastic, ceramic or glass is used as the electrically insulating material.
 31. Method according to claim 20, whereby the pipe is a double pipe with an inside pipe and an outside pipe, whereby the inside pipe and the outside pipe are produced from electrically insulating material.
 32. Method according to claim 31, Whereby the process gas is guided into the inside pipe; and Whereby a buffer gas is guided into the outside pipe.
 33. Method according to claim 32, whereby the buffer gas is a different gas than the process gas.
 34. Method according to claim 33, whereby the buffer gas is an inert gas.
 35. Method according to claim 32, whereby the buffer gas is fed to the outside pipe at a pressure that is different from the pressure at which the process gas is fed to the inside pipe.
 36. Method according to claim 20, whereby the process gas is fed at a pressure that is below the atmospheric pressure.
 37. Method according to claim 20, whereby the process gas is fed at a pressure that is approximately 1% to approximately 15% of the ambient pressure of the pipe below the ambient pressure of the pipe. 